Effect of combined interval training on the cardiorespiratory fitness in heart failure patients: a systematic review and meta-analysis

Background: The combination of interval training and resistance training has showed interesting results in chronic heart failure patients, corroborating the benefits of physiological adaptations of both protocols. Objective: To evaluate the effect of the combination of interval training and resistance training program when compared to interval training alone and/or without intervention group on cardiorespiratory fitness in patients with chronic heart failure. Methods: We search MEDLINE via PubMed, ScienceDirect, Sportdiscus, BIREME and Scielo, from their inception to December 2018. Were included both randomized and non-randomized controlled trials comparing the effect of combined training, interval training alone and/or WI group on VO2peak (expressed in ml/kg/min), in people with chronic heart failure patients. The meta-analysis was conducted via Review Manager v 5.3 software, using random effect model. Results: Ten articles were selected (nine randomized controlled trial), involving 401 participants. Six studies compared combined training with interval training and six studies compared combined training with the without intervention group. Eighty percent of the trials presented moderate risk of bias and twenty percent low risk of bias. Data showed significant difference and major increase in VO2peak in favor to combined training group compared to interval training group (SMD = 0.25; CI =0.04-0.46) and without intervention group (SMD =0.46; CI =0.29-0.64), respectively. Conclusion: The combination of interval training and resistance training showed more effective in increasing cardiorespiratory fitness in patients with heart failure than interval training alone and non-exercise therapy. However, further studies should be conducted to increase the understanding of this combined training method. (C) 2019 Associacao Brasileira de Pesquisa e Pos-Graduacao em Fisioterapia. Published by Elsevier Editora Ltda. All rights reserved.